Add default implementation of NondetModel.areAllChoiceActionsUnique().

Copied from MDPExplicit. Removed (mostly) from elsewhere.

prism/src/automata/LTSFromDA.java

@@ -164,12 +164,6 @@ public class LTSFromDA extends ModelExplicit implements LTS
 		return null;
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		return false;
-	}
-
 	@Override
 	public int getNumTransitions(int s, int i)
 	{

prism/src/explicit/LTSExplicit.java

@@ -89,13 +89,6 @@ public class LTSExplicit extends ModelExplicit implements LTS
 		return null;
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		// as we don't assign action labels, they are not unique
-		return false;
-	}
-
 	@Override
 	public int getNumTransitions(int s, int i)
 	{

prism/src/explicit/MDPExplicit.java

@@ -27,8 +27,6 @@
 
 package explicit;
 
-import java.util.HashSet;
-
 import strat.MDStrategy;
 
 /**
@@ -36,26 +34,6 @@ import strat.MDStrategy;
  */
 public abstract class MDPExplicit extends ModelExplicit implements MDP
 {
-	// Accessors (for NondetModel)
-	
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		HashSet<Object> sActions = new HashSet<Object>();
-		for (int s = 0; s < numStates; s++) {
-			int n = getNumChoices(s);
-			if (n > 1) {
-				sActions.clear();
-				for (int i = 0; i < n; i++) {
-					if (!sActions.add(getAction(s, i))) {
-						return false;
-					}
-				}
-			}
-		}
-		return true;
-	}
-
 	// Accessors (for MDP)
 
 	@Override

prism/src/explicit/NondetModel.java

@@ -27,6 +27,7 @@
 package explicit;
 
 import java.util.BitSet;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.function.IntPredicate;
 
@@ -76,8 +77,28 @@ public interface NondetModel extends Model
 
 	/**
 	 * Do all choices in in each state have a unique action label?
+	 * <br><br>
+	 * NB: "true" does not imply that all choices are labelled,
+	 * e.g., an a-labelled choice and an unlabelled one _are_ considered unique;
+	 * multiple unlabelled choices are _not_ considered unique.
 	 */
-	public boolean areAllChoiceActionsUnique();
+	public default boolean areAllChoiceActionsUnique()
+	{
+		int numStates = getNumStates();
+		HashSet<Object> sActions = new HashSet<Object>();
+		for (int s = 0; s < numStates; s++) {
+			int n = getNumChoices(s);
+			if (n > 1) {
+				sActions.clear();
+				for (int i = 0; i < n; i++) {
+					if (!sActions.add(getAction(s, i))) {
+						return false;
+					}
+				}
+			}
+		}
+		return true;
+	}
 	
 	/**
 	 * Get the number of transitions from choice {@code i} of state {@code s}.

prism/src/explicit/STPGAbstrSimple.java

@@ -438,12 +438,6 @@ public class STPGAbstrSimple extends ModelExplicit implements STPG, NondetModelS
 		return null;
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		throw new RuntimeException("Not implemented");
-	}
-
 	@Override
 	public boolean allSuccessorsInSet(int s, int i, BitSet set)
 	{

prism/src/explicit/SubNondetModel.java

@@ -289,12 +289,6 @@ public class SubNondetModel implements NondetModel
 		return model.getAction(sOriginal, iOriginal);
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		throw new RuntimeException("Not implemented");
-	}
-
 	@Override
 	public int getNumTransitions(int s, int i)
 	{

prism/src/explicit/modelviews/MDPAdditionalChoices.java

@@ -185,13 +185,6 @@ public class MDPAdditionalChoices extends MDPView
 		return (additional == null) ?  null : additional.get(choice - numOriginalChoices);
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		return model.areAllChoiceActionsUnique() && super.areAllChoiceActionsUnique();
-	}
-
-
 
 	//--- MDP ---
 

prism/src/explicit/modelviews/MDPDroppedAllChoices.java

@@ -169,12 +169,6 @@ public class MDPDroppedAllChoices extends MDPView
 		return model.getAction(state, choice);
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		return model.areAllChoiceActionsUnique() ? true : super.areAllChoiceActionsUnique();
-	}
-
 	@Override
 	public Iterator<Integer> getSuccessorsIterator(final int state, final int choice)
 	{

prism/src/explicit/modelviews/MDPDroppedChoicesCached.java

@@ -186,12 +186,6 @@ public class MDPDroppedChoicesCached extends MDPView
 		return model.getAction(state, originalChoice);
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		return model.areAllChoiceActionsUnique() ? true : super.areAllChoiceActionsUnique();
-	}
-
 	@Override
 	public Iterator<Integer> getSuccessorsIterator(final int state, final int choice)
 	{

prism/src/explicit/modelviews/MDPView.java

@@ -27,7 +27,6 @@
 
 package explicit.modelviews;
 
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map.Entry;
 import java.util.PrimitiveIterator;
@@ -89,25 +88,6 @@ public abstract class MDPView extends ModelView implements MDP, Cloneable
 
 	//--- NondetModel ---
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		final HashSet<Object> actions = new HashSet<Object>();
-		for (int state = 0, numStates = getNumStates(); state < numStates; state++) {
-			final int numChoices = getNumChoices(state);
-			if (numChoices <= 1) {
-				continue;
-			}
-			actions.clear();
-			for (int choice = 0; choice < numChoices; choice++) {
-				if (!actions.add(getAction(state, choice))) {
-					return false;
-				}
-			}
-		}
-		return true;
-	}
-
 	@Override
 	public SuccessorsIterator getSuccessors(final int state, final int choice)
 	{

prism/src/param/ParamModel.java

@@ -429,13 +429,6 @@ public final class ParamModel extends ModelExplicit implements MDPGeneric<Functi
 		return null;
 	}
 
-	@Override
-	public boolean areAllChoiceActionsUnique()
-	{
-		// we don't know
-		return false;
-	}
-
 	/**
 	 * Allocates memory for subsequent construction of model. 
 	 *